A gala is a special social occasion usually with some form of entertainment and often in an elegant setting.
The pronunciation of gala is often subject of debate. Two prevalent pronunciations of gala exist, one in which gala is pronounced as GAH-luh, with a short "a" and another, often used in American English that is pronounced as GAY-luh.
Modern usage of the word gala derives from either 17th century Italian or Spanish where it was and still is pronounced with a short "a".
The word gala is also related to the word "gallant", which is pronounced with a short "a".
Due to these reasons, the most appropriate pronunciation of gala is likely GAH-luh.
However, the alternative pronunciation of gala as GAY-luh is still widely accepted.